The popularity of wireless telecommunication has given rise to the recognition of physical limitations on available bandwidth and uniformity concerns. Accordingly, a need for standardization has permeated the telecommunications industry. In January 1998, the European Telecommunications Standard Institute—Special Mobile Group (ETSI SMG) agreed on a radio access scheme for Third Generation Radio Systems called Universal Mobile Telecommunications Systems (UMTS). To further implement the UMTS standard, the Third Generation Partnership Project (3GPP) was formed in December 1998. 3GPP continues to work on a common third generational mobile radio standard.
A typical UMTS system architecture in accordance with current 3GPP specifications is depicted in FIG. 1. The UMTS network architecture includes a Core Network (CN) interconnected with a UMTS Terrestrial Radio Access Network (UTRAN) via an interface known as Iu which is defined in detail in the current publicly available 3GPP specification documents.
The UTRAN is configured to provide wireless telecommunication services to users through User Equipments (UEs) via a radio interface known as Uu. The UTRAN has base stations, known as Node Bs in 3GPP, which collectively provide for the geographic coverage for wireless communications with UEs. In the UTRAN, groups of one or more Node Bs are connected to a Radio Network Controller (RNC) via an interface known as Iub in 3GPP. The UTRAN may have several groups of Node Bs connected to different RNCs, two are shown in the example depicted in FIG. 1. Where more than one RNC is provided in a UTRAN, inter-RNC communication is performed via an Iur interface.
Fundamental to 3GPP and the architecture of other relatively sophisticated systems is the adoption of a multi-layer structure such as the Open Systems International (OSI) seven layer model which was developed by the International Organization of Standardization (ISO).
The OSI model which is implemented through 3GPP systems has a physical layer in respective stations, base stations and user equipment, which actually transmits and receives the wireless telecommunication signals. The physical layer is commonly referred to as Layer 1 or L1. Other standard layers include a data link layer, Layer 2 (L2); a network layer, Layer 3 (L3); a transport layer, Layer 4 (L4); a session layer, Layer 5 (L5); a presentation layer, Layer 6 (L6); and an application layer, Layer 7 (L7). Through the layered hierarchy, communication information and data is conveyed over various predefined channels where the information is formatted and distributed through the functioning of the higher layers and then passed to the physical layer for actual transmission. The layered structure and associated channel definitions and data format structures as defined by 3GPP Technical Specifications provide for a highly sophisticated and relatively efficient data communication system.
One function implemented in 3GPP systems is paging. Under current 3GPP Technical Specification such as TS25.221 and TS25.331 V3.1.2.0, the paging function is implemented utilizing two different data signals namely, a Page Indication (PI) and substantive paging data. In accordance with current 3GPP specification, a PI is sent on a page indication channel (PICH) in advance of the substantive page data. That data is sent on a separate paging channel (PCH) which is transported by a Secondary Common Control Physical Channel (SCCPCH).
Since base stations are transmitting information for many UEs, an individual UE only needs to process that portion of the information being broadcast from the base stations that relates to that particular UE. In order to process paging data, a UE monitors a PICH until it receives an appropriate PI designated for that UE. After the appropriate PI signal is received by the UE, that UE then knows that substantive paging data is being sent for it on an associated PCH via an SCCPCH. Otherwise, the UE need not process paging data on the SCCPCH, such as paging data intended for a different UE.
To avoid the need for unnecessary processing of data intended for other UEs, a UE's physical layer, L1, is selectively instructed by the UE's higher layers as to which signals to process and the manner in which the signals are to be processed in accordance with the format of those signals. Much of the direct control of the physical layer is conducted by the data link layer, Layer 2, which in turn receives instructions and information from the network layer, Layer 3, which typically includes a radio resource control (RRC). The RRC provides information to the L1 control processing elements in Layer 2 to instruct the physical layer, L1, to process data received on specific channels such as a predefined SCCPCH.
In 3GPP systems, each SCCPCH has a specific format for transporting data which, as noted above, can include data for a paging channel (PCH). A base station may broadcast more than one paging channel with the use of multiple PICHs and PCHs. However, current 3GPP specifications dictate that only one PCH may be carried by a SCCPCH and that a unique PICH is defined for each PCH. Where multiple PICHs are being broadcast, the UEs make a determination as to which PICH it can monitor for a PI signal using a known algorithm as set forth in TS25.304 V3.11.0 Section 8.
Once the selection of which paging channel the UE should monitor is made, the RRC in level 3 directs the L1 control to instruct the physical layer to process signals received on the appropriate PICH. At that time, because there is a one-to-one correspondence with the PICHs and the PCHs, it is known which PCH and accordingly which SCCPCH is associated with the PICH which the physical layer has been instructed to monitor. Once the UE receives an appropriate PI over the PICH which it is monitoring, the physical layer L1 of the UE must be instructed to process the data on the SCCPCH which is carrying the associated PCH in order to process the associated paging data.
As shown in FIG. 2, conventional implementations have the PICH processed at the physical layer L1, but the decision to receive PCH is made by higher layers, typically within the RRC. Therefore, the processed paging indicator data is sent by L1 processing to the L1 Controller of L2 then on to the RRC in L3 which signals L1 processing via L1 Control of L2 to receive and process the PCH data if the paging indicator is positive. L1 Control is the Layer 2/3 interface to Layer 1.
For illustrative and comparative purposes, FIG. 2 shows a fairly typical example where there is a two frame gap between a PI and the corresponding paging data. The size of the gap is known in the radio link and transport channel (RL/TR) configuration for PCH reception.
As shown in FIG. 2, conventionally the physical layer L1 conducts chip processing of the received (RX) signal for each frame as it is received and then processes the received frames in accordance with the manner it has been configured by the L1 Controller of Layer 2. Thus, the physical layer L1 decodes the PI received on the PICH it is monitoring by the end of the received frame, Frame #1, in which the PI is contained. Implicit in FIG. 2, is that the physical layer L1 has been preconfigured by the L1 Controller to monitor the particular PICH based on instructions received from the RRC.
When decoded, the PI is sent by L1 to the physical layer Control processing unit of L2 which in turn requests new instructions from the RRC of L3 based on the decoded PI. The RRC then responds to the control processor of L2 instructing it to configure the physical layer L1 to process paging data from a specific PCH. The L2 processor in turn configures the physical layer for PCH to process paging data received on the specified PCH. This instruction process typically spans in time about one and one half frames, i.e. completely over Frame #2 which follows the frame in which the PI was received and into the next frame, Frame #3. The paging data is sent in the next frame, Frame #4, at which time the physical layer L1 has already been configured to receive the paging data in the selected PCH and follows those configuration instructions to process the paging data during Frame #5, i.e. after the conclusion of receipt/chip processing of the paging data in Frame #4.
The present inventors have recognized that the configuration of the physical layer L1 to process the paging data indicated by a PI can be performed more efficiently.